Gender differences in the use of cardiovascular interventions in HIV-positive persons; the D:A:D Study

Peer reviewe

Data from an International Multi-Centre Study of Statistics and Mathematics Anxieties and Related Variables in University Students (the SMARVUS Dataset)

This large, international dataset contains survey responses from N = 12,570 students from 100 universities in 35 countries, collected in 21 languages. We measured anxieties (statistics, mathematics, test, trait, social interaction, performance, creativity, intolerance of uncertainty, and fear of negative evaluation), self-efficacy, persistence, and the cognitive reflection test, and collected demographics, previous mathematics grades, self-reported and official statistics grades, and statistics module details. Data reuse potential is broad, including testing links between anxieties and statistics/mathematics education factors, and examining instruments’ psychometric properties across different languages and contexts

Controlled deposition of iron oxide on the surface of zirconia by the molecular designed dispersion of Fe(acac)(3)

The reaction of Fe(acac)3 with the surface of zirconia has been studied for the first time using in situ infrared diffuse reflectance spectroscopy, photoacoustic spectroscopy, and Fourier transform Raman spectroscopy. The unstable Fe(acac)3 reacts readily with the surface of zirconia at room temperature in the liquid phase or at 110 C in the gas phase, yielding grafted Fe-OH species and Zr-acac surface groups. We present evidence that the reaction occurs both with coordinatively unsaturated Zr sites and with the surface hydroxyls. The grafted Zr-acac groups are thermally unstable and form Zr-acetate groups after thermal treatment at 110 C in ambient air. After removal of the organic ligands, noncrystalline iron oxide species are formed on the zirconia surface. The grafting of iron oxide on zirconia is a relevant procedure to form either redox catalysts or solid-state fuel cells

Growth of iron oxide on yttria-stabilized zirconia by atomic layer deposition

The growth and thermal stability of an iron oxide overlayer on yttria-stabilized zirconia (YSZ) have been studied using atomic layer deposition (ALD), mainly in combination with low-energy ion scattering (LEIS). These techniques form a powerful combination, where ALD is designed for controlled (sub)monolayer deposition, while LEIS selectively probes the altered outermost atomic layer. The Fe(acac)3 precursor reacts already at room temperature with YSZ. The reaction proceeds until saturation, which is characteristic for ALD. After the results of repeated ALD cycles, which consist of Fe(acac)3 deposition followed by an oxidation treatment, have been studied, a model could be proposed which describes the growth mode of the iron oxide layer on YSZ. Oxidation at temperatures of 800 °C and higher causes a migration of Fe2O3 into the bulk, limiting its usefulness in surface catalytic processes at these temperatures. At 800 °C the diffusion coefficient of Fe in YSZ is determined to be 10-23 m2/s. The reaction mechanism of Fe(acac)3 with the YSZ surface is studied using infrared diffuse reflectance. The results reveal more than one reaction mechanism, but there seems to be a preference for the reaction via coordinatively unsaturated sites

Growth of iron oxide on yttria-stabilized zirconia by atomic layer deposition

The growth and thermal stability of an iron oxide overlayer on yttria-stabilized zirconia (YSZ) have been studied using atomic layer deposition (ALD), mainly in combination with low-energy ion scattering (LEIS). These techniques form a powerful combination, where ALD is designed for controlled (sub)monolayer deposition, while LEIS selectively probes the altered outermost atomic layer. The Fe(acac)3 precursor reacts already at room temperature with YSZ. The reaction proceeds until saturation, which is characteristic for ALD. After the results of repeated ALD cycles, which consist of Fe(acac)3 deposition followed by an oxidation treatment, have been studied, a model could be proposed which describes the growth mode of the iron oxide layer on YSZ. Oxidation at temperatures of 800 °C and higher causes a migration of Fe2O3 into the bulk, limiting its usefulness in surface catalytic processes at these temperatures. At 800 °C the diffusion coefficient of Fe in YSZ is determined to be 10-23 m2/s. The reaction mechanism of Fe(acac)3 with the YSZ surface is studied using infrared diffuse reflectance. The results reveal more than one reaction mechanism, but there seems to be a preference for the reaction via coordinatively unsaturated sites